1. Field of the Invention
The present invention relates to a cooling device for use on an off-road vehicle, and more particularly to a structure for arranging a cooling device in position on an off-road vehicle.
2. Description of the Relevant Art
Japanese Laid-Open Patent Publication No. 60/134042, for example, discloses an off-road vehicle including a vehicle frame primarily comprising a pair of main pipes spaced from each other transversely of the vehicle and extending longitudinally thereof, the main pipes having rear ends joined to each other, a central roll bar of a substantially inverted U shape mounted longitudinally on the main pipes, and a rear roll bar interconnecting the rear ends of the main pipes and the upper end of the central roll bar. A driver's seat is disposed between the main pipes in front of the central roll bar. An engine is disposed between the main pipes behind the central roll bar.
Air-cooled engines are generally employed in off-road vehicles. Where a water-cooled engine is mounted on an off-road vehicle, care should be exercised in selecting the position where the radiator is installed. More specifically, the radiator should be positioned so as to prevent it from being hit by small stones and other foreign matter. The radiator should also be easily accessed for maintenance without disassembling the complex vehicle frame.
To cool cooling water flowing through the radiator, a fan rotatable by a fan motor is provided behind the radiator. As shown in Japanese Laid-Open Utility Model Publication No. 50/42274, for example, the fan is supported on a bracket or an attachment stay mounted on the engine. Since the radiator on the frame of the off-road vehicle is exposed, it is necessary to locate fan attachment components in a position concealed from external view and also to reduce the number of such fan attachment components so that the fan as it is installed will be advantageously good appearance.
If a reservoir tank is associated with the radiator, the reservoir should be positioned as closely to the radiator as possible and at substantially the same height as the radiator. This is because a pipe between the reservoior and the radiator can be shortened, the layout of the reservoir and the radiator can advantageously be developed, and a sufficient amount of cooling water can be drawn from the reservoir tank when the temperature of cooling water in an upper tank of the radiator is lowered and a vacuum is produced in the upper tank. However, the arrangement of the reservoir tank and the radiator should be carefully designed since if the reservoir tank was located immediately in front of the radiator and at the same height as the radiator, a sufficient amount of air would not be supplied to the core of the radiator.